Table 1.
Baseline demographic and clinical characteristics of study participants at week 4
| All | Boosted | Primed | Unvaccinated | ||
|---|---|---|---|---|---|
| Total, n (%) | 328 | 87 (26.5) | 86 (26.2) | 155 (47.3) | |
| Age, years | |||||
| Mean, SD | 42.0 (14.5) | 44.3 (17.0) | 41.7 (14.2) | 40.9 (13.0) | |
| 18–29 | 73 (22.3%) | 18 (20.7%) | 23 (26.7%) | 32 (20.6%) | |
| 30–49 | 160 (48.8%) | 40 (46.0%) | 34 (39.5%) | 86 (55.5%) | |
| 50–64 | 67 (20.4%) | 17 (19.5%) | 23 (26.7%) | 27 (17.4%) | |
| ≥ 65 | 28 (8.5%) | 12 (13.8%) | 6 (7.0%) | 10 (6.5%) | |
| Gender | |||||
| Female | 242 (73.8%) | 58 (66.7%) | 68 (79.1%) | 116 (74.8%) | |
| Male | 86 (26.2%) | 29 (33.3%) | 18 (20.9%) | 39 (25.2%) | |
| Race / Ethnicity | |||||
| White or Caucasian (not Hispanic or Latino) | 234 (71.3%) | 63 (72.4%) | 65 (75.6%) | 106 (68.4%) | |
| Black or African American | 13 (4.0%) | 2 (2.3%) | 2 (2.3%) | 9 (5.8%) | |
| Hispanic | 44 (13.4%) | 9 (10.3%) | 16 (18.6%) | 19 (12.3%) | |
| Asian | 16 (4.9%) | 7 (8.1%) | 2 (2.3%) | 7 (4.5%) | |
| Patient Refused | 9 (2.7%) | 4 (4.6%) | 0 (0.0%) | 5 (3.2%) | |
| Other | 12 (3.7%) | 2 (2.3%) | 1 (1.2%) | 9 (5.8%) | |
| CMS Geographic Region (n, %) | ** | ||||
| Region 1: ME, NH, VT, MA, CT, RI | 15 (4.6%) | 4 (4.6%) | 4 (4.7%) | 7 (4.5%) | |
| Region 2: NY, NJ, PR, VI | 9 (2.7%) | 4 (4.6%) | 2 (2.3%) | 3 (1.9%) | |
| Region 3: PA, DE, MD, DC, WV, VA | 31 (9.5%) | 11 (12.6%) | 8 (9.3%) | 12 (7.7%) | |
| Region 4: KY, TN, NC, SC, GA, MS, AL, FL | 116 (35.4%) | 29 (33.3%) | 26 (30.2%) | 61 (39.4%) | |
| Region 5: MN, WI, IL, MI, IN, OH | 47 (14.3%) | 10 (11.5%) | 17 (19.8%) | 20 (12.9%) | |
| Region 6: NM, OK, AR, TX, LA | 59 (18.0%) | 19 (21.8%) | 21 (24.4%) | 19 (12.3%) | |
| Region 7: NE, IA, KS, MO | 16 (4.9%) | 3 (3.5%) | 6 (7.0%) | 7 (4.5%) | |
| Region 8: MT, ND, SD, WY, UT, CO | 1 (0.3%) | 1 (1.2%) | 0 (0.0%) | 0 (0.0%) | |
| Region 9: CA, NV, AZ, GU | 33 (10.1%) | 5 (5.8%) | 2 (2.3%) | 26 (16.8%) | |
| Region 10: AK, WA, OR, ID | 1 (0.3%) | 1 (1.2%) | 0 (0.0%) | 0 (0.0%) | |
| US Geographic Region | * | ||||
| Northeast | 41 (12.5%) | 11 (12.6%) | 11 (12.8%) | 19 (12.3%) | |
| South | 188 (57.3%) | 56 (64.4%) | 50 (58.1%) | 82 (52.9%) | |
| Midwest | 63 (19.2%) | 13 (14.9%) | 23 (26.7%) | 27 (17.4%) | |
| West | 36 (11.0%) | 7 (8.1%) | 2 (2.3%) | 27 (17.4%) | |
| Previously Tested Positive | 121 (36.9%) | 32 (36.8%) | 28 (32.6%) | 61 (39.4%) | |
| Work in healthcare | 37 (11.3%) | 9 (10.3%) | 13 (15.1%) | 15 (9.7%) | |
| Work in high-risk setting | 33 (10.1%) | 8 (9.2%) | 14 (16.3%) | 11 (7.1%) | |
| Live in high-risk setting | 16 (4.9%) | 3 (3.5%) | 6 (7.0%) | 7 (4.5%) | |
| Social vulnerability index, Mean (SD) | 0.43 (0.22) | 0.36 (0.20) | 0.44 (0.22) | 0.47 (0.21) | *** |
| Self-Reported Comorbiditya | |||||
| Number of comorbidities, Mean (SD) | 0.35 (0.65) | 0.39 (0.62) | 0.41 (0.77) | 0.30 (0.59) | |
| Asthma or Chronic Lung Disease | 30 (9.2%) | 11 (12.6%) | 7 (8.1%) | 12 (7.7%) | |
| Cirrhosis of the liver | 1 (0.3%) | 0 (0.0%) | 1 (1.2%) | 0 (0.0%) | |
| Immunocompromised Conditions or Weakened Immune Systemb | 16 (4.9%) | 0 (0.0%) | 10 (11.6%) | 6 (3.9%) | *** |
| Diabetes | 11 (3.4%) | 4 (4.6%) | 3 (3.5%) | 4 (2.6%) | |
| Heart Conditions or Hypertension | 41 (12.5%) | 14 (16.1%) | 9 (10.5%) | 18 (11.6%) | |
| Overweight or obesity | 16 (4.9%) | 5 (5.8%) | 5 (5.8%) | 6 (3.9%) | |
| At least 1 comorbidity | 87 (26.5%) | 28 (32.2%) | 24 (27.9%) | 35 (22.6%) | |
| Index dayc acute COVID-19 symptoms | |||||
| Number of acute COVID-19 symptoms, Mean (SD) | 5.4 (2.6) | 4.7 (2.5) | 5.7 (2.5) | 5.6 (2.6) | ** |
| Systemic symptoms | |||||
| Fever | 127 (38.7%) | 22 (25.3%) | 35 (40.7%) | 70 (45.2%) | ** |
| Chills | 165 (50.3%) | 27 (31.0%) | 48 (55.8%) | 90 (58.1%) | *** |
| Muscle or Body Aches | 183 (55.8%) | 36 (41.4%) | 52 (60.5%) | 95 (61.3%) | ** |
| Headache | 224 (68.3%) | 51 (58.6%) | 62 (72.1%) | 111 (71.6%) | |
| Fatigue | 204 (62.2%) | 48 (55.2%) | 56 (65.1%) | 100 (64.5%) | |
| Respiratory symptoms | |||||
| Shortness of Breath or Difficulty Breathing | 42 (12.8%) | 6 (6.9%) | 13 (15.1%) | 23 (14.8%) | |
| Cough | 243 (74.1%) | 65 (74.7%) | 63 (73.3%) | 115 (74.2%) | |
| Sore Throat | 187 (57.0%) | 53 (60.9%) | 50 (58.1%) | 84 (54.2%) | |
| New/Recent Loss of Taste or Smell | 35 (10.7%) | 7 (8.1%) | 13 (15.1%) | 15 (9.7%) | |
| Congestion or Runny Nose | 247 (75.3%) | 69 (79.3%) | 72 (83.7%) | 106 (68.4%) | * |
| GI symptoms | |||||
| Nausea or Vomiting | 42 (12.8%) | 7 (8.1%) | 11 (12.8%) | 24 (15.5%) | |
| Diarrhea | 69 (21.0%) | 14 (16.1%) | 15 (17.4%) | 40 (25.8%) | |
SD Standard Deviation
*P < 0.05; **P < 0.01; ***P < 0.001 for the statistical tests of comparisons between Boosted cohort, Primed cohort, and Unvaccinated cohort
aSVI ranges from 0 to 1. A community with higher value is more socially vulnerable
bImmunocompromised conditions includes compromised immune system (such as from immuno-compromising drugs, solid organ or blood stem cell transplant, HIV, or other conditions), conditions that result in a weakened immune system, including cancer treatment, and kidney failure or end stage renal disease
cCOVID-19 test nasal swab day